The Met police said the cost of their crimes totalled at least £5.1 million.
Four phone thieves based in London have been jailed for handling more than 5,000 stolen phones.
Two of the four men were convicted of spending thousands of pounds from their victim’s bank accounts.
Over an 18-month period the group handled phones that had been stolen from across the capital, and two of the men made purchases or took out loans using the devices.
Some of the victims had money taken straight from their bank account, while others had payments come out for designer clothes worth hundreds.
The Met police said the cost of their crimes totalled a whopping £5.1 million.
The police believe many of the phones were sold abroad after the criminals had handled them.
They found 170 phones, but estimate that the group has had thousands of victims.
On Thursday, the four men - Nazih Cheraitia, 34, Zakaria Senadjki, 31, Ahmed Abdelhakim Belhanafi, 25, and Riyadh Mamouni, also 25 - were sentenced for the crimes.
Commander Owain Richards, from the Metropolitan Police, said: “I want to commend the borough based local officers involved for their excellent work in tracking down these individuals and ensuring they were brought to justice.
“We do not underestimate the impact these crimes have on Londoners and are doing all we can to tackle phone thefts.
“This includes increased policing in hotspot areas and making better use of technology.
“However we need the phone companies to play their part and make it more difficult for criminals to re-sell these stolen devices. The Met will be speaking with them in the coming weeks to push this issue even further.”
The group was tracked down by local officers from Lambeth and Southwark after multiple victims of theft and robbery reported they had tracked their stolen phones to two main addresses in London.
The Police investigated two blocks of flats as part of what they call Operation Ringtone, where they use tracking devices in phones to be able to locate them.
Some of the phones found by police. Picture: Met police
Officers have not been able to track down the owners of all the phones seized as not all were reported as stolen.Last year, more than 64,000 mobile phones were reported to the police as stolen in London, through theft or robbery – double the previous two years.
The Met has urged anyone who has had a lost or stolen phone to use the national mobile phone register so recovered phones can be restored.
They also urge phone users to take steps to further protect themselves from fraud, by ensuring they have a strong password, two-factor authentication and turning off message previews so thieves cannot see any messages about reset or log in codes when phones are locked and ensuring they have written down and safely stored their IMEI number.